The Sedalia weekly bazoo. [volume] (Sedalia, Mo.) 187?-1904, 1887-11-29
SPONGE AND STEEL
4 Ffre-CrestinE Combination Equal 60
Greasy Rags and Hay.

- S-STS1kuk sonDtnntiOu Equal 20
Greasy Rags and Hay.
One of the most curious instances of
spontaneous ignition on record is that
recently reported by Chicago manu-
facturer of plane bits. For some time
q sponge had been used for wetting an
emery wheel in his shop, bringing
water up out of water-box by capil-
larry attraction, and touching the wheel.
Ii was kept against the wheel lightly
by spring. The wheel was used in
grinding very hard steel plates, there
fore the sponge constantly wiped par
ticles of steel off the wheel during its
revolutions, and il was used in that
way until these particles had filled up
its cells to a very considerable degree.
of course being wet all the time. 1t
was then laid aside, the string being
still attached to it together with little
cotton cloth. In time it became en-
tirely dry, lying on and against a
couple of pieces of fine wood. After
lying unobserved for q week or ten
days. it was suddenly discovered one
afternoon to be incandescent-in fact
a living coal-and to having set fire
both to the board on which it rested
and the one against which it leaned. Ii
had burned a considerable portion of
the stout Irvine and the cotton cloth
attached to it. All were smoldering,
and although flames had not burst
forth, they evidently would have done
so in a short time, as the room con-
tanned a very pungent smell of burn
ing wood. The boards were each burned
to a depth of a quarter of an inch
and to width approximately three
inches when the incipient confagration
was quenched. The appearance Of the
charred sponge was not unlike that OF
a piece of roasted iron ore. which it
differed from. however, very decidedly
in weight. being quite light. When
broken il exhibited the same character
isties throughout showing that the
fine particles Of steel had been thor
oughly distributed in its interior. This
evident case Of spontaneous ignition Of
an article which had not been saturated
with grease or oil. but which consisted
Of 3 piece of ordinary sponge, filled
with fine particles of steel while it was
in Q wet state. naturally caused much
discussion, but a very plausible eI-
PLANTATION Of its mysterious behavior
has been made by the manufacturer
himself. as follows: The particles of steel
which were wiped off the emery wheel
by the sponge must necessarily have
been exceedingly fine. as the steel was
very hard. Lodging on.the sponge in a
wet condition and in constant contact
with water. oxidation was active-or,
in other words, the particles rusted
very rapidly. The fine particles of
steel presented an extremely great sur
face area for such action as compared
with their bulk. Under ordinary cir
cumstances oxidation does not develop
sensible heat, but under the peculiar
conditions here realized the usually
harmless chemical phenomenon of rust
ing developed into an actual fire
creating agent, and incandescence re-
suited. Here was an article which at
first sight would seem to be as incapa-
BILE of spontaneous combustion as an
ordinary brick, but which proves to be
entitled to rank with greasy rags and
oily waste and other well established
fire-creating combinations. Had not
this burning mass been discovered
most auspiciously. serious cOnfagra-
ton would. in all probability, have
ensued, and its cause would have
been unknown" Fire and Water.